Pulverizing-machine.



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PATENTED JULY 17, 1906. G. L. PRATT.

PULVERIZING MACHINE. APPLICATION FILED MAR.17, 1903. RENEWED JUNE 2.1906.

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PULVERIZING MACHINE. APPLICATION FILED MAB..17, I903. RENEWED JUNE 2.1906.

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N0. 826,062. PATENTED JULY 17, 1906.

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PULVERIZING MACHINE.

APPLICATION FILED MARJ'I, 190s. RENEWED JUNE 2.1906.

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N0. 826,062. Q PATBNTED JULY 17, 1906. G. L. PRATT.

PULVERIZING MACHINE. APPLICATION FILED MAR.17, 190a. RENEWED JUNE 2.1906.

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" NITED STATES PATENT OFFICE.

PULVERIZING-MACHINE.

Specification of Letters Patent.

Patented July 17, 1906.

Application filed March 17, 1903. Renewed June 2, 1906, Serial No. 319,921.

To all whom 7'25 may concern.-

Be it known that I, GEORGE LEwIs PRATT, a citizen of the United States, residing at Atlanta, in the county of Fulton and State of Georgia, have invented certain new and useful Improvements in Pulverizing-Machines;v

and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The object of my invention is to provide a simple and thoroughly efficient form of pulverizing machine or mill; and it comprehends the construction, arrangement, and combination of parts as hereinafter set forth.

In the drawings representing an apparatus embodying my invention in my preferred form, Figure 1 is a vertical axial section. Fig. 2 is a side elevation. Fig. 3 is a horizontal section onthe line 3 8, Fig. 1. Fig. 4 is a section on the line 4 4, Fig. 2. Fig. 5 shows the feeding device, and Fig. 6 is a modification in which the rollers are straight in contour instead of conical and vertically suspended instead of at an angle.

Referring to the drawings, the bed-plate A is made of any desired shape, preferably circular, and is provided with holes a for foundation-bolts. On the base are pedestals a, and a curved annular flange a constituting a pan, which flange is connected with the base A by radial ribs 01*, thus forming apertures a between the ribs. The outer portion of the ribs a connect with an annular flan e a which carries a drum or casin a.

On the inner face of the pan a is secured a conical pulverizing-rmg B, which also protects the pan from wear.

Legs or standards 0 are secured to the pedestals a and extend upward for a dis-.

The bottom of the pan a is a convex screen F, bolted to the flange a and now and hereinafter in the specification and claims whereever I use the term convex, as applied to my screen, I desire to be understood to mean a screen elevated at its center and gradually sloping or flaring toward the edges, the screen thus projecting u ward into the interior of thepan. The a vantage in forming the screen convex is that the material poured into the pan is kept in a constant state of agitation by sliding over the inclined surface of the screen toward the conical pulverizingring, and thus the material is continuously presented in the path of movement of the pulverizing-rollers for crushing. This is a very important and valuable feature of my invention, as if the screen were made flat the pulverizing-rollers would have to be depended upon to agitate the material, which would only partly be successful, a portion of the material in that case always remaining in the center of the pan untouched by the rollers.

A spider G is bolted to the standards and at its center carries a bearing 9 A verticalshaft H revolves in the bearing, and its upper end revolves in a bearing in the head 0 The upperend of the shaft has an enlarged surface or collar 0 by which it is supported.

A horizontal shaft K is mounted in suitable bearings 716 176 and may be driven by a pulley 74. A beveled gear k is secured to this shaft and meshes with a bevel-gear a, secured to the vertical driving-shaft, by which the vertical shaft is rotated.

At the lower end of the shaft H is secured the head M. On this head are a number of boxes m preferably three pairs. In these boxes rotate journals n, that are secured to boxes M. In each ofthese boxes n is secued a shaft 71?, arranged transversely to the journal 12 and held in place by jam-nuts 12 On each shaft n is pivoted a pulverizing-' roller 17?, having on its bottom, integrally formed therewith, conical projections or studs n constituting plows, which also serve to keep the material in the pan constantly agitated and .preventin possible sticking of the material. The rol er is preferably secured to a bearing a, running on the shaft. This bearing may have a follower or stufling-box n to keep out dust from the bearings, while the lower part has a plate n inclosing an enlarged end or collar n", secured to the shaft. The roller n is preferably solid, but may have a conical facing that engages the conical enlargement of the bearing a and is secured thereon by a jamnut a having locking-bolts a On the head M, that is suitably braced by ribs m, are conduits 0, each having an opening arranged tangential to the movement of the head and facing in the direction of rotation of the head, so that when the head is revolved the air will be forced into the. conduit. The conduits are preferably arranged in proximity to each of the shafts a, so that the air entering the opening 0 will be forced past the shaft 01 and the upper portion of the bearing n, tending to keep the bearing cool. After passing the bearings the conduit is hop per-shaped, terminating in nozzles 0", preferably directed toward the conical screen E.

The side-screen members of the pan being inclined, the pulverulent material will be thrown on them by the centrifugal motion of the rollers, while the jarring or vibration incident to all such machines will cause the fine particles to pass through, while the coarser particles will slide down over the stationary pulverizing member. At the same time the blast of air will aid the smaller particles to pass through the apertures. The spring-supporting of the screen at T also con duces to increased vibration thereof, facilitating the passage of pulverulent material therethrough.

.lVIaterial is fed into the pulverizing-mill -through a suitable hopper R and then passes through another hopper R and is fed into a drum S, connected with the head. From this head the material passes through apertures s s 8 down into the pan in proximity to the pulverizing-rollers. l/Vhen the main shaft is rotated, the centrifugal action, as well as their own weight, will cause the rollers a strongly to engage the conical pulverizingring B, and it will be understood that the friction between these surfaces will cause the rollers to revolve on the shafts M, as usual in chasing-rolls. The freedom of the tangential horizontal pins n in their boxes'm will permit the rolls to have a movement to and from the pulverizing-ring. It will be noted that in addition to the centrifugal force that will tend to rotate the shafts on this pin and move the rollers away from the axis of the driving-shaft the weight of the rollers and shaft would also tend to move them in a radial direction. This latter force would have a tendency to relieve the strain on the pins it caused by the weight of the rolls. As material is reduced between the pulverizing-surfaces, part thereof falls onto the bottom screen, and that of sufficient fineness passes therethrough. The centrifugal action will cause part of the ground material to be thrown against the screen E, and this force,

together with that of the automatic air-' blast, and the spring-supporting of the screen will cause some of the material to pass seaoee through screen E, whence it falls through channels a in the base. The air-blast will not only tend to keep the bearings of the rollers cool and free from dust, but will also serve to eject some material from the pan through the conical screen E.

Fig. 6 shows a modification in which the grinding-face of the ring is arranged vertical,

and the rods are also vertically disposed; but

the side screen is still inclined, as is the bottom screen.

In order to assist vibration I may provide suitable abutments or ridges P onthe grinding-ring B, which will engage the rollers and raise them from the. surface slightly, and

' then the rollers will fall onto the ring again,

thus producing the desired effect.

Having thus fully descibed my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In a pulverizing-machine, a pan for the material to be pulverized, having its bottom formed as a convex screen, projecting upward into the interior of the pan.

2. In a pulverizing-machine, a pan for the material to be pulverized, having its bottom formed as a convex screen, projecting upward into the interior of the pan, and pulverizing members disposed within the pan.

3. In a pulverizing-machine, a pan for the material to be pulverized, having its bottom formed as a convex screen,projecting upward into the interior of the pan, and pulverizing members disposed within the pan and arranged with their pulverizing-surfaces inclined to the vertical and horizontal lines.

4. In a pulverizing-machine, a pan for the material to be pulverized, having its bottom formed as a convex screen,projecting upward into the interior of the pan, and pulverizing members disposed within the pan and having ppward and outward flaring pulverizing-suraces.

5. In a pulverizing-machine, a pan for the material to be pulverized, having its bottom formed as a convex screen, and pulverizing members disposed within the pan and carrying on their under side conical studs, or plowpoints, integrally formed with the pulverizing members.

6. In a pulverizing-machine, a pan, with outward-flaring sides, for the material to be pulverized, having its bottom formed as a convex screen, projecting upward into the interior of the pan, and movable pulverizing members disposed within the pan and arranged with their pulverizing-surfaces inclined to the vertical and horizontal lines.

7. In a pulverizing-machine, a pan for the material to be pulverized, having its bottom formed as a convex screen, a conical, stationary, pulverizing member disposed within the an, and movable, conical, pulverizing-rollers adapted to engage the conical, stationary member.

8. In a pulverizing-machine, a pan for the material to be pulverized, having its bottom formed as a convex screen, and having a screen disposed in its sides.

9. In a pulverizing-machine, a pan for the material to be pulverized, having its bottom formed as a convex screen, and having an inclined screen disposed in its sides.

10. In a pulverizing-machine, a pan adapted for the material-to be pulverized, having its bottom formed as a convex screen, and

having a screen in its sides, and movable pulverizing-rollers disposed Within the pan.

11. In a pulverizing-machine, a pan for the material to be pulverized, having its bottom formed as a convex screen, and having a screen in its sides, a conical, stationary, pulverizing-ring disposed Within the pan, and movable, pulverizing-rollers adapted to engage the ring.

12. In a pulverizing-machine, a pan for the material to be pulverized, having its bottom formed as a convex screen, a conical, stationary pulverizing-ring disposed Within the pan, and rotatable pulverizing-rollers adapted to engage the stationary ring.

13. In a pulverizing-machine, a pan for the material to be pulverized, having its bottom formed as a convex screen, a conical, stationary, pulverizing-ring disposed Wi thin the pan, and movable pulverizing-rollers adapted to engage the conical rin and arranged With their axes inclined to t e vertical and horizontal lines.

14. In a pulverizing-machine, a pan for the material to be pulverized, having its bottom formed as a convex screen, and having a screen in its sides, a conical, stationary, pulverizing-ring disposed within the pan, movable pulverizing-rollers adapted to engage the ring and arranged With their axes inclined to the vertical and horizontal lines, and means disposed Within the pan for effecting vibration of the screens.

1 5. In a pulverizing-machine, a pan for the material to be pulverized, having its bottom formed as a convex screen, and having a spring-supported screen in its sides, a conical, stationary, pulverizin -ring disposed Within the pan, and movl ole pulverizing-rollers adapted to on age the ring and arranged with their axes inc ined to the vertical and horizontal lines.

1 6. In a pulverizing-machine, a pan for the material to be pulverized, having its bottom formed as a convex screen, and having a.

spring-supported screen in its sides, a conical, stationary, pulverizing-ring disposed Within the pan, movable pulverizing-rollers adapted to engage the rin and arranged With their axes inclined to the vertical and horizontal lines, and means disposed Within the pan for eflecting vibration of the screens.

In testimony whereof I affix my signature in the presence of two subscribing Witnesses.

GEO. LEWIS PRATT.

Witnesses:

T. BARTOW FORD, N.- P. PRATT. 

